The present invention is directed to integrated circuits. More particularly, the invention provides a power saving system and method for application specific integrated circuit (ASIC) devices. Merely by way of example, the invention has been applied to very large scale integration (VLSI) chips that include ASIC circuits. But it would be recognized that the invention has a much broader range of applicability.
Integrated circuits or “ICs” have evolved from a handful of interconnected devices fabricated on a single chip of silicon to millions of devices. Current ICs provide performance and complexity far beyond what was originally imagined. In order to achieve improvements in complexity and circuit density (i.e., the number of devices capable of being packed onto a given chip area), the size of the smallest device feature, also known as the device “geometry”, has become smaller with each generation of ICs. Semiconductor devices are now being fabricated with features less than a quarter of a micron across.
Increasing circuit density has not only improved the complexity and performance of ICs but has also provided lower cost parts to the consumer. An IC fabrication facility can cost hundreds of millions, or even billions, of dollars. Each fabrication facility will have a certain throughput of wafers, and each wafer will have a certain number of ICs on it. Therefore, by making the individual devices of an IC smaller, more devices may be fabricated on each wafer, thus increasing the output of the fabrication facility. Making devices smaller is very challenging, as a given process, device layout, and/or system design often work down to only a certain feature size.
Integrated circuits have a variety of applications. For example, ASIC is a type of chip that has been produced for particular application. For example, ASIC have been designed and use for cellular telephones. Generally, feature, size, and power consumption of ASIC devices important characteristics. Excessive power consumption is typically an undesirable characteristic. Excessive power consumption not only causes high energy costs, but also can generate a significant amount of heat that adversely affects device performance and even damages device components if proper protective measures are not adopted.
In the past, various techniques have been used to reduce power consumption for ASIC circuits. For example, dynamic variable power-supply (DVP) system has been a conventional techniques used to reduce power consumption. Unfortunately, conventional techniques such as the DVP system are often inadequate.
From the above, it is desirable to have an improved technique for power control of ASIC devices.